I was wondering if anyone could possibly help me with a problem on my 4.5 80, when I brought it the lpg system worked brilliantly but after taking it off-road for the first time with a fair bit of bouncing and crashing about it now stalls whilst approaching junctions when running on lpg (but fine on petrol), I should say it's an auto and also the only thing I can see that it might be is a white wire with purple stripe that's spliced into a green wire on the throttle position sensor I've traced it back to the bulk head but it's just hanging there not connected to anything and I can't work out for the life of me where the hell it should be connected to? Please help
LPG TPS WIRE BROKEN
- Thread starter Posworth
- Start date
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Do you have a pic of the system? Is it injection or venturi type?
From the stalling at intersections that you describe, sounds like it is a venturi system and your gas pressure is low and doesn't provide enough LPG at low vacuum. There should be a small valve leading to the gas venturi that you can adjust to increase the amount of gas. Adjust it in 1/4 turns, I'm pretty sure, counterclockwise is more LPG clockwise is less, but I haven't adjusted mine in a long time I could be the opposite.
From the stalling at intersections that you describe, sounds like it is a venturi system and your gas pressure is low and doesn't provide enough LPG at low vacuum. There should be a small valve leading to the gas venturi that you can adjust to increase the amount of gas. Adjust it in 1/4 turns, I'm pretty sure, counterclockwise is more LPG clockwise is less, but I haven't adjusted mine in a long time I could be the opposite.
if you can post up more details, pictures - we can see if we can help. I have a direct injector LPG on my 1997 but had TB LPG before that
- Thread starter
- #6
I tried adjusting the valve at 1/4 turns but made no difference on the stalling and adjusted it to the point it wouldn't even idle anymore so I don't think it's that, it was fine before I went offroading a few months back I added a pic of that wire I think may have broken off from somewhere and the other end where it attaches to the TPS
if that wire is broken and was tapped off the TPS then it needs to reconnect to it.
Do another picture where you showed the broken wire (where does it go to on the other end)
also a different view of the TPS (to see where it was connected)
It needs the TPS measurement to see how much (normally with O2 connection as well) LPG to squirt in
Do another picture where you showed the broken wire (where does it go to on the other end)
also a different view of the TPS (to see where it was connected)
It needs the TPS measurement to see how much (normally with O2 connection as well) LPG to squirt in
- Thread starter
- #8
You can see on the last pic where it's spliced into the green wire on the TPS and the other pic of me holding it is the opposite end up on the bulk head but I just cannot find where on earth it goes? There are no visible broken wires near to it, that's why I was wondering if anyone knew where it might need to be reattached?
I presume it runs fine on petrol and "only" issue is when you manually switch it over to LPG (or auto via temp swtich)?
Did you get it installed before or done via prev. owner?
Any access to who installed it to ask them?
Any LPG installers locally?
Can you find online (more specifically the LPG ECU maker) and find their electronic wiring diagram. At least in that way you can figure out what connects to what. Phoning around a few LPG installers you'll find who resellers what LPG brands and pick their brains
You could "chance" connecting the broken wire back to the TPS (or touch/hold it 'connected') while switching in the LPG and see if any effect
Did you get it installed before or done via prev. owner?
Any access to who installed it to ask them?
Any LPG installers locally?
Can you find online (more specifically the LPG ECU maker) and find their electronic wiring diagram. At least in that way you can figure out what connects to what. Phoning around a few LPG installers you'll find who resellers what LPG brands and pick their brains
You could "chance" connecting the broken wire back to the TPS (or touch/hold it 'connected') while switching in the LPG and see if any effect
What you have is a venturi system. It is not "smart" and doesn't rely on sensors. It turns off your fuel pump and starts flowing gas. the only regulation you have is that small valve just before your venturi tube. If it is stalling, not enough gas is being drawn in at low vacuum, off accelerator, or idle. It is possible since you were beating around off road that one of the seals in the vaporizer could be damaged, but the truck would still run.
I'm assuming that when you adjusted the valve and closed it, that you also turned it all the way open too, correct? Crank it all the way open and try to get it to stall, If it doesn't stall, adjust it back down until it does, then open it again. I had the same problem and this worked for me.
Once you get it running you might consider upgrading to one of these BLOS LPG Carburators instead of the venturi. blos carb | eBay
I got much better power and mileage after putting this on my 4.5 fuel injected truck
I'm assuming that when you adjusted the valve and closed it, that you also turned it all the way open too, correct? Crank it all the way open and try to get it to stall, If it doesn't stall, adjust it back down until it does, then open it again. I had the same problem and this worked for me.
Once you get it running you might consider upgrading to one of these BLOS LPG Carburators instead of the venturi. blos carb | eBay
I got much better power and mileage after putting this on my 4.5 fuel injected truck
